The NINCDS Collaborative Perinatal Project has provided a large prospectively defined pediatric population, unselected for level of risk, in which to investigate the prevalence and natural history of the most common convulsive disorder of childhood, febrile seizures. A series of papers has delineated the natural history of febrile seizures, identified risk factors for unfavorable outcome, and reviewed the effect of sample selection on outcome. An NIH Consensus Development Conference on Long-term Management of Children with Febrile Seizures was held. Results of the consensus conference have been published in professional and lay journals, and the papers were edited for a monograph, published in 1981. A major study to evaluate the effects of medications and of recurrent seizures is soon to begin under contract. We have collaborated in designing a study on the EEG as a predictor in febrile seizures, and in a survey on management of febrile seizures.